This disclosure relates to systems and methods for fabricating and installing a hidden hinge door for use in residential and commercial buildings. Hidden hinge doors of the type disclosed here, typically look like an article of furniture attached, built-in, or placed adjacent to a wall, that can be moved to reveal an opening in the wall. One example might be a bookcase that appears to be built into a wall that can be rotated like a door to provide a passageway through the wall. The system and method described in this disclosure can also be used for a very heavy door (in a residential or commercial building) that looks like a door, but needs a hidden hinge and support system with the functionality described herein.
Some of the challenges in making a reliable high-quality hidden hinge door include:    a) Must support heavy weight. For example, if the door is an actual bookcase filled with actual books, or paper files, the weight of this paper would be considerably greater than the weight of a normal door. A hardbound 200-page book that is 6 inches by 9 inches weighs about 0.7 pounds. If there were 300 books of this size in the bookcase, the total weight of the books would be over 200 pounds. A 3-foot drawer for holding 8.5×11 inch files can hold about 18 reams of paper, each of which weighs about 6 pounds, which means a total of over 100 pounds per file drawer.    b) Accurate alignment and fit. There should not be any obvious visible gaps or skews. Thus, the bookcase should be placed and oriented correctly in six degrees of freedom: three mutually perpendicular linear axes and three mutually perpendicular rotations. The three mutually perpendicular linear axes would typically be a horizontal (right-left) or x-axis, a vertical (up-down) or y-axis, and an axis perpendicular to the wall (going in and out) or z-axis. The three mutually perpendicular rotations would typically be rotation about the x-axis, rotation about the y-axis, and rotation about the z-axis. Rotation about the x-axis can also be called pitch and represents a movement in and out of the top of the bookcase relative to the bottom of the bookcase. Rotation about the y-axis can also be called yaw and represents a movement in and out of the left side of the bookcase relative to the right side of the bookcase. Rotation about the z-axis can also be called roll and represents a clockwise or counterclockwise rotation of the bookcase when looked at from the front. A good system would include adjustment possibilities in all six of these degrees of freedom to ensure that the bookcase can be correctly aligned when installed.    c) Rigidity. The structure and its mounting must maintain alignment in the three axes and three rotations at all positions with its heavy load.    d) No visible hinges. There should not be any exposed hinges like there are for a normal door. If the hinges were visible, this would not be a “hidden hinge door”.    e) Large rotation. A bookcase is thick (or deep) and width of the opening in which it sits is limited, which means that the bookcase should rotate as close to a full 180 degrees as possible. If the bookcase cannot rotate far enough, the width when the “door” is open is reduced. For example, if the wall opening is 30 inches wide and the bookcase is 10 inches deep, one third of the opening is blocked if the case only rotates 90 degrees.    f) Adaptability. The frame system for the bookcase should fit a range of wall openings. Conventional doors and door openings in a wall come in different widths and heights. To minimize the number of stock-keeping units (SKUs), the frame hardware should accommodate a broad of wall opening widths and height. The frame hardware should be the same for doors that swing from the right or the left.    g) Compact shipping. The cost of shipping a pre-assembled hidden hinge door system (including bookcase, storage cabinet or similar) is much more than shipping only structural components in a smaller box to be assembled on-site using a locally fabricated article of furniture (bookcase, storage cabinet, etc).    h). Ease of installation.
This disclosure describes novel embodiments designed to best fulfill the above needs.
It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood that the invention is not necessarily limited to the particular embodiments illustrated herein.